Due to the recent improvement in hardware performance, the home-use entertainment apparatus has made possible to render real time three-dimensional CG, thus realizing practical three-dimensional CG animations.
In such real-time three-dimensional CG, the shadow volume method is known as an art to render, real time, a shadow of another object onto an arbitrary position in a surface of an object represented as a 3D model.
The shadow volume method determines, concerning the light from a light source, a region undergoing an effect from another object and then represents a shadow by decrease of luminance in that region.